Windows Management Instrumentation (WMI) is a vaguely defined mechanism for
the control of platform-specific devices; laptop functions like special
buttons, LEDs, and the backlight are often controlled through WMI
interfaces. On Linux, access to WMI functions is restricted to the kernel,
while Windows allows user space to use them as well. A recent proposal to
make WMI functions available to user space in Linux as well spawned a
slow-moving conversation that turned on a couple of interesting questions —
only one of which was anticipated in the proposal itself.[$] User-space access to WMI functions
Source: LWN.Net